For over half a century, the 9-1-1 (911) call system has been widely utilized by North America for emergency response situations. The three-digit telephone number 911 has been designated as the “Universal Emergency Number” for citizens throughout the United States to request emergency assistance. It is intended as a nationwide telephone number and gives the public fast and easy access to a Public Safety Answering Point (PSAP). Approximately 96% of the geographic US is covered by some type of 911 call system.
Conventional wired communication systems, such as wired landline telephones, utilize a specific emergency response implementation referred to as enhanced 911 (E911). Using E911, when a caller dials 911, the caller's telephone number and location are automatically sent to a 911 operator. Location is an important concept in the way that the E911 works. Location determination depends upon entries located within an Automatic Location Information (ALI) database. The ALI database information provides the automatic display at the PSAP of the caller's call back number, the address or location of the caller and, in some cases, supplementary emergency services information.
Conventional mobile phone communication systems utilize mobile positioning centers (MPCs) to locate callers who dial 911 from mobile phones. The MPC serves as the entity that retrieves, forwards, stores and controls position data within the location network. It can select the Position Determining Entity (PDE) to use in position determination and forwards the position to the requesting entity or stores it for subsequent retrieval. In other words, the mobile position center is the database, process, or service within a communication system that determines the physical position of a mobile device.
Increasingly, phone systems are using voice over Internet protocol (VoIP). VoIP is a technology that allows a caller to make voice calls using a broadband Internet connection instead of a conventional (or analog) phone line. VoIP services convert voice audio into digital signals that travel over a network, including the Internet. When calling a regular phone number from a VoIP number, the signal is converted to a conventional telephone signal before it reaches the destination. VoIP calls can be made directly from a computer, a special VoIP phone, or a traditional phone connected to a special adapter. In addition, wireless “hot spots” in locations such as airports, parks, and cafes with connection to the Internet may enable use of VoIP service wirelessly.
With its portability, cost savings, and the promise of enhanced functionality, Internet-based telephony is becoming the de facto choice in various jurisdictions. VoIP has a range of advantages including being a flexible communication system. For example, an end user, assigned a specific VoIP number for a VoIP phone at a first physical location, can receive calls sent to that VoIP number in the first physical location via the VoIP phone, and also have the VoIP number configured to port calls received from the VoIP number to another VoIP phone or mobile device of the end user when the end user is remote from the first physical location, e.g., at a second physical location. As such, the VoIP number can travel with the end user such that the end user can be accessible via a single VoIP number at different locations.
However, in contrast to the emergency location look-up protocols of conventional wired communication systems, the virtual nature of VoIP can raise issues in the context of emergency response situations. For emergency response, conventional VoIP systems use a VoIP positioning center (VPC) to identify the location of a caller requesting emergency assistance using a VoIP phone line. VPC systems, however, may use an outdated database and do not take into account situations where an end user has dialed 911 using a VoIP line but the end user is not located at the physical location normally associated with the VoIP number as defined in the VPC.
It is with these observations in mind, among others, that various aspects of the present disclosure were conceived and developed.